1. Field of the Invention
The present invention is directed to a hybrid cabling system and network for in-building wireless (IBW) applications.
2. Background
The continuing expansion of wireless communication and its accompanying wireless technology will require many more “cell sites” than currently deployed. This expansion has been estimated from a doubling to a ten-fold increase in the current number of cell sites, particularly in the deployment of 4G/LTE. This dramatic increase in the number of cell sites is due, in large part, to the high bandwidth demand for wireless applications and the bandwidth to the cell site must be shared to the available UE (user equipment) within range of the site.
Better wireless communication coverage is needed in order to get the bandwidth to the increasing number of customers that demand it. Thus, in addition to new deployments for traditional, large “macro” cell sites, there is an increasing need in the expansion of “micro” cell sites (sites within structures, such as office buildings, schools, hospitals, and residential units). In-Building Wireless (IBW) Distributed Antenna Systems (DASs) are utilized to improve wireless coverage within buildings and related structures. Conventional DAS uses strategically placed antennas or leaky coax throughout a building to accommodate radio frequency (RF) signals in the 300 MHz to 6 GHz frequency range. Conventional RF technologies include TDMA, CDMA, WCDMA, GSM, UMTS, PCS/cellular, iDEN, WiFi, and many others.
Outside the United States, carriers are required by law in some countries to extend coverage inside buildings. In the United States, bandwidth demands and safety concerns will drive IBW applications, particularly as the world moves to current 4G architectures and beyond.
There are a number of network architectures for distributing wireless communications inside a building that are known. These include choices of passive, analog/amplified RF, RoF (Radio over Fiber, also known as RFoG, or RF over glass), and fiber backhaul to pico and femto cells. There are hybrids of these architectures also, such as an RoF vertical or riser distribution with an extensive passive coaxial distribution from a remote unit to the rest of the horizontal cabling (within a floor, for example).
Active architectures generally include manipulated RF signals carried over fiber optic cables to remote electronic devices which reconstitute the electrical signal and transmit/receive the signal. Passive architectures include components to radiate and receive signals, usually through a punctured shield ‘leaky coax’ network. Hybrid architectures include native RF signal carried optically to active signal distribution points which then feed multiple coaxial cables terminating in multiple transmit/receive antennas. These conventional architectures can have limitations in terms of electronic complexity and expense, inability to easily add services, inability to support all combinations of services, distance limitations, or cumbersome installation requirements.
Conventional cabling for IBW applications includes RADIAFLEX™ cabling available from RFS (www.rfsworld.com), standard ½ inch coax for horizontal cabling, ⅞ inch coax for riser cabling, as well as, standard optical fiber cabling for riser and horizontal distribution.
Also, physical and aesthetic challenges exist in providing IBW cabling for different wireless network architectures, especially for older buildings and structures. These challenges include gaining building access, limited distribution space in riser closets, and space for cable routing and management.